A fire has caused widespread damage to Latvia's historic Riga Castle.

The blaze started on Thursday and took more than 70 fire-fighters, a helicopter and all the city's fire engines to put out.

The castle, an official residence of the country's president, also houses the National History, Art and Music Museums as well as a collection of literature, according to Latvian media.

The president was not in the castle when the fire broke out, as the building was under renovation.

The blaze damaged the castle's roof, attic and two upper floors, local media reported.

The cause of the fire and the condition of the museum artefacts remain unknown.